Updated win32 portable build script.

prepare_portable.py:
 Added new site-packages tornado and qrcode.
 Fix incorrect exclude patterns. (by Andy)
 Do not exclude unittest from bundled modules for portable (by Andy)
Updated license files for win32.
requirements.txt: Updated all required packages and current version numbers.
MANIFEST.in: updated file structure
Merge pull request #587 from emanuelschuetze/portable

Updated win32 portable build script.
Fixed issue #585. Sort group members by first name or last name in group detail view according to config variable
Merge pull request #589 from normanjaeckel/SortingOnGroupDetailView

Fixed issue #585. Sort group members by first name or last name in group...
Protection for participant managers, Issue #122

Raises a validation error, if a non-superuser user edits himself and
removes the last group containing the permission to manage participants
Merge pull request #591 from normanjaeckel/WarningRechtAufRechte

Protection for participant managers, Issue #122
New Overlay API
Merge pull request #592 from ostcar/overlay

New Overlay API
fixed error on new overlay api
Merge pull request #593 from ostcar/master

Fixed Error in new Overlay API
New Feature: List of speakers.
Updated template and some minor fixed for list of speakers. Updated projector slide.
List of speakers. Part 2
Merge pull request #588 from ostcar/speaker_list

List of speakers
Fixed #553: Switch projector control scroll arrows
Merge pull request #594 from emanuelschuetze/last-1.4a1-changes

Fixed #553: Switch projector control scroll arrows
Use Fabric in travis and insert a fabfile for developers
Merge pull request #596 from normanjaeckel/Fabric

Use Fabric in travis and insert a fabfile for developers
Update fabfile to reinsert coverage plain report to travis
Merge pull request #598 from normanjaeckel/UpdateFabfile

Update fabfile to reinsert coverage plain report to travis